[Avodah] what G-d can't do

[Eli Turkel]

<<The opposing view is that yes, He can make a five-sided triangle, or an
object that measures 2.5 amot long, but when put into a 20-amah wide room
doesn't take up any of those 20 amot.  According to this view, He can make
a rock so heavy that He can't lift it, and He can still lift it, because
He is not bound by the Law of Non-Contradiction.>>

According to all views he cannot make a 5 sided triangle or make 1+1=3.
These are definitions and have nothing to do with logic. A five sided
figure is defined
as a pentagon not a triangle. Two is defined as the number after 1 and
so the sum
(assuming standard arithmetic) os one and one is two.

However putting down 2 one inch rulers after each other and saying it
gives two inches
is a fact of the universe and is no longer a definition. In a thought
experiment the
two could combine to give less than 2 inches.

In short one must distinguish between mathematics which is conceptual and
physics which describes the world. G-d can change the rules of the universe but
he can't change a definition.

<<> Ralbag often explains away, and occasionally even rejects outright,
> statements of Hazal that he considers to contradict True Philosophy.
> See, e.g., Breishis [biur milos ha'parshah] 1:29 and Bamidbar 22:21.  I
> plan to discuss this in depth in a paper for Hakirah.

And for that very reason not everyone considers the Ralbag to be 100%
kosher.>>

In this case I think all rishonim agree that G-d cannot do anything
against logic.
It was only later kabbalists/chassidim that stressed G-d's omnipotence that
the idea emerged that G-d could perform acts against logic or laws of
the universe.

I would venture that this is connected to the idea that "most"
rishonim feel that
G-d does not change the rules to give reward and punishment in this world except
for special people. Everyone else is governed by the usual rules. The
kabbalists/chassidim
argued "that a leaf doesn't fall without G-d ordering it".  Again the kabbalists
stressed the powers of G-d in all circumstances while rishonim tended to accept
nature and G-d interfered with nature (which he established once) only when
necessary.

-- 
Eli Turkel